The present invention relates to surgical devices and, in particular, it concerns a surgical tool for surgical tool for removing a block of tissue or other material from an organ or other body.
U.S. Pat. No. 7,041,114 to the present inventor describes a surgical method for removing a piece of tissue from within soft body tissue, and particularly, for extracting a tissue block from the angle of the eye, as well as corresponding surgical tools. The technique described therein is highly advantageous, providing reliable extraction of a block of tissue with a well defined shape and dimensions through a small incision. In the context of the ocular surgery procedure described, extraction of a block of trabecular tissue is achieved via a corneal approach through a self-sealing flap, thereby avoiding trauma to vascularized tissue of the eye. The aforementioned patent is hereby incorporated by reference as if fully set out herein.
Despite these advantages, the specific device described in the aforementioned patent relies upon mechanical interaction between shaped blades and the tissue itself in order to direct the path of the blades. More specifically, each blade is formed with a “deflection feature” which is a sharp projection bent towards the surface of the tissue so as to lodge in the tissue and start cutting a slit diverging from the initial insertion slit when moved. While this approach has been found effective, it may be at risk of non-uniform results due to variations in the mechanical properties of the tissue between different patients and variations in the way in which the tool is manipulated by a surgeon.
There is therefore a need for a surgical tool for removing a block of material from a body which would include a mechanical actuation arrangement including a number of springs for controlling deflection of the blades, thereby improving repeatability and reliability of the tissue sampling technique described in the aforementioned patent,